Outlet fitting for a portable turbine

ABSTRACT

An outlet fitting for portable turbines used in paint spraying, the outlet fitting including an exhaust pipe threadedly carrying an annular reducer sized to closely interfit with a cylindrical exhaust tube of the turbine and sealed thereto with an O-ring, with the outlet fitting secured to a wall of an enclosure for the turbine by a decorative ring.

BACKGROUND OF THE INVENTION

This invention relates to the field of portable turbines useful inair-atomization spray painting, particularly in the field of highvolume, low pressure (HVLP) air atomized paint spraying.

In the past an air mover in the form of a turbine was developed andmanufactured for vacuum cleaner applications. Such turbines often, butnot always, had a plastic outlet housing including a plastic exhausttube. In vacuum cleaner applications, the inlet or suction side was ofmost interest. In the present application, it has been found desirablefrom a cost standpoint to utilize such a large outlet turbine to provideatomization air for HVLP spray painting. The turbine was put into anenclosure and the outlet of the turbine was desirably connected via ahose to a hand-held spray gun. The exhaust tube of such turbines, whileeconomic, was not suitable for direct connection to the air hose, beingof a larger diameter and not having any means to retain the hose to theexhaust tube, the end portion of which was generally a simple cylinder.The present invention allows utilization of such economic turbines byproviding an outlet fitting that is itself economical and easy toinstall, and which further provides a convenient and secure means toremovably attach the spray gun air hose exteriorly of the enclosurecontaining the turbine. Additionally, the outlet fitting of the presentinvention allows quick and easy disassembly of the turbine from thefitting should service or replacement of the turbine be required.Additionally, when the exhaust tube of such turbines was made ofplastic, attempts to thread an adapter or reducer into the exhaust tubewere found to result in fracture and consequent destruction of theexhaust tube, a result which is avoided with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a turbine enclosure useful in thepractice of the present invention.

FIG. 2 is a partially cut away end view of the enclosure of FIG. 1, alsoshowing a spray gun and hose useful in the practice of the presentinvention.

FIG. 3 is an exploded view of the enclosure of FIG. 1 showing partscontained therein.

FIG. 4 is an enlarged view of a portion of FIG. 3, showing certaindetails of the outlet fitting of the present invention.

FIG. 5 is a side view of a large outlet turbine useful in the practiceof the present invention.

FIG. 6 is a view of a first end of the turbine of FIG. 5.

FIG. 7 is a view of a second end of the turbine of FIG. 5.

FIG. 8 is an exploded view of the outlet fitting of the presentinvention, together with a fragmentary perspective view of a wall of theenclosure of FIG. 1.

FIG. 9 is a fragmentary, partial section view of the outlet fitting ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, and most particularly to FIGS. 1 and 2, aturbine enclosure 30 useful in the practice of the present invention maybe seen. Enclosure 30 has a bottom housing 22, a top housing 25, and twofilter cans or housings 5. A handle 26 is provided for carryingenclosure 30 and an electrical cord 70 is used to power the portableassembly. An ON-OFF switch 28, indicator light 27, and fuse holder 24are located in top housing 25. A cup holder 23 forms a part of theenclosure 30 and is sized to receive a paint cup 72 of a hand-held spraygun 74. An air hose 76 is used to connect the gun to the turbine inenclosure 30. An air fan filter 6 is provided at one end of theenclosure 30 and is retained by one of the filter housings 5.

Referring now also to FIG. 3, air for the turbine inlet is drawn througha two stage filter 11 in the other filter housing 5. A pair of identicalfilter screens 7 each support one of the filters 6 and 11, respectively,and a pair of foam fan noise rings 8 are included interior of the filterhousings to suppress noise. In addition an additional foam silencer 12can be used to suppress noise generated by turbine 17. Turbine 17 ispreferably mounted to a sheet metal can cover 15 by bolts 13, spacers16, washers 18 and nuts 19. An annular foam disk 14 seals the inlet sideof turbine 17 against cover or plate 15. Similarly, a second can coveror plate 9 completes the filter can assembly at the other end ofenclosure 30. Preferably sheet metal screws 4 are used to secure covers9 and 15 to their respective filter housings 5.

A plastic or nylon cylindrical member 10 is preferably installed on theend of every other one of the sheet metal screws 4 to provide canmounting feet for each of the filter can subassemblies, and to provide aspacer function for securing each of the filter can subassembliesbetween the grooved flanges of the top and bottom housings 25, 22.

A perforated metal vent plate 21 permits motor cooling air to exhaustthe enclosure 30. Four cap screws 20 are preferably used to secure thetop and bottom housings 25, 22 together, retaining the filter canassemblies at each end of enclosure 30.

Turning now to FIGS. 4 and 8, the outlet fitting 2 of the presentinvention may be seen in more detail. Outlet fitting 2 includes anannular reducer member 34, an O-ring 3, an exhaust pipe 42, and adecorative ring 1. Fitting 2 is assembled by placing O-ring 3 in agroove 52 at a first end 48 of reducer 34. Reducer 34 is then preferablyassembled on pipe 42 by interengaging internal threads 36 in a throughbore 35 in reducer 34 with a first set of external threads 44 at a firstend 46 of pipe 42 until reducer abuts an intermediate unthreaded portion62, as shown by phantom line 78 in FIG. 9. A second end 60 of exhaustpipe 42 is then preferably inserted through an aperture 80 in a wall 82of the bottom housing 22 of enclosure 30. An internally threadeddecorative ring 1 is then preferably received on a second set 58 ofexternal threads 58 at the second end 60 of pipe 42. Ring 1 can then betightened on threads 58 to secure pipe 42 to wall 82 since a shoulderformed by the unthreaded portion 62 is larger in diameter than aperture80.

Referring now also to FIGS. 5, 6, and 7, more details of the turbine 17useful in the practice of the present invention may be seen. Turbine 17preferably has a plastic housing and exhaust tube molded as a unit 84and indicated by speckling in FIGS. 5-7. It is to be understood,however, that unit 84 may be formed of other materials, such as die-castaluminum, as an alternative to plastic. Turbine 17 is mounted inenclosure 30 by three projections 86, each having an aperture 88therethrough to receive one of the mounting bolts 13. Air is drawn in aninlet aperture 90 of turbine 17, compressed and delivered via an exhausttube 32. Tube 32 exhausts air generally tangentially of turbine 17 andalong a cylindrical axis 92. Tube 32 is to be understood to becylindrically shaped at its outlet end, concentric to axis 92. It is tobe further understood that when outlet fitting 2 is installed inaperture 80, it will be coaxially aligned with and axially spaced apartfrom tube 32 along axis 92, when the turbine 17 is installed inenclosure 30. Once fitting 2 and turbine 17 are thus aligned, reducermember 34 is preferably "backed-off" or partially unthreaded along pipe42, causing O-ring 3 to become compressed between an interior diameter94 of tube 32 and the annular reducer 32 to prevent air from leakingtherebetween. Once the outlet fitting is installed, air exiting theturbine 17 is directed to pass through the annular reducer 32 and theexhaust pipe 42 where it is presented at the exterior of the enclosure30 for transmission via hose 76 to spray gun 74. As may be seen in FIG.2, a threaded connector 96 is preferably provided on one end of hose 76for connection to threads 58 on pipe 42. As may be seen most clearly inFIG. 9, wall 82 is preferably generally perpendicular to axis 92 of tube32.

The invention is not to be taken as limited to all of the detailsthereof as modifications and variations thereof may be made withoutdeparting from the spirit or scope of the invention. For example,reducer 34 may be made of somewhat resilient material if desired toeliminate O-ring 3. Furthermore, but not by way of limitation, mountingmeans 50, which in the embodiment shown includes ring 1, may be anyother suitable means, such as a press or threaded or snap fit with wall82, or a clip or retaining ring (for example) may be used in place ofthreaded ring 1.

What is claimed is:
 1. An outlet fitting combination with a portableturbine carried in an enclosure, the turbine having an exhaust tube offixed internal diameter, the outlet fitting in combination with theturbine and enclosure, the outlet fitting comprising:a) an annularreducer member having a bore therethrough carrying internal threads andhaving an external diameter at a first end thereof closely interfittingthe internal diameter of the exhaust tube of the portable turbine; andb) an exhaust pipe having a first set of external threads thereon at afirst end thereof to matingly engage the internal threads of the annularreducer and wherein the exhaust pipe further has mounting means securingthe exhaust pipe to the enclosure of the turbine.
 2. The outlet fittingcombination of claim 1 wherein the reducer further comprises an externalgroove at the first end thereof and wherein the outlet fitting furthercomprises:c) an O-ring carried in the groove sealing the fitting to theexhaust tube.
 3. The outlet fitting combination of claim 1 wherein themounting means comprises an internally threaded decorative ring receivedon a second set of external threads located at a second end of theexhaust pipe distal of the first set of threads and exterior of theenclosure.
 4. The outlet fitting combination of claim 3 wherein theexhaust pipe further comprises an unthreaded portion intermediate thefirst and second sets of threads, the unthreaded portion having adiameter larger than a diameter of the second set of threads.
 5. Theoutlet fitting combination of claim 1 wherein the exhaust tube of theturbine is formed of plastic.
 6. The outlet fitting combination of claim1 wherein the exhaust tube of the turbine is formed of aluminum.
 7. Amethod of connecting to the outlet of a turbine having an exhaust tubecomprising the steps of:a) threading an annular reducer having a boretherethrough onto an exhaust pipe; b) installing the exhaust pipe in awall of an enclosure for the turbine and in alignment with an exhausttube of the turbine; and c) backing the annular reducer along thethreads of the exhaust pipe until the reducer is received in the exhausttube of the turbine.
 8. The method of claim 7 wherein step a) furthercomprises installing an O-ring on the exterior of the annular reducerand step c) further comprises compressing the O-ring between an interiordiameter of the exhaust tube and the annular reducer to prevent air fromleaking between the exhaust tube and the annular reducer when thereducer is received in the tube.
 9. The method of claim 7 wherein stepb) further comprises inserting the exhaust pipe through an aperture inthe wall of the enclosure and threading a decorative ring on the exhaustpipe exterior of the wall to retain the pipe to the wall.
 10. A combinedoutlet fitting, turbine and enclosure assembly for portable paintspraying, the assembly comprising:a) a turbine having a generallycylindrical exhaust tube projecting along a cylindrical axis; b) anenclosure carrying the turbine and having a wall spaced apart from thecylindrical exhaust tube and positioned generally perpendicularly to thecylindrical axis of the exhaust tube; c) an outlet fitting havingi) anexhaust pipe threaded at one end thereof, and ii) an annular reducerhaving a bore therethrough threadably received on the exhaustpipe;wherein the outlet fitting is secured to the wall of the enclosureand projects generally perpendicularly thereto and interiorly of theenclosure in alignment with the cylindrical axis, and further whereinthe annular reducer is received in and seals against the cylindricalexhaust tube of the turbine to direct air exiting the turbine to passthrough the annular reducer and the exhaust pipe for delivery exteriorof the enclosure.
 11. The assembly of claim 10 further comprisingiii) athreaded end on the exhaust pipe projecting exteriorly of the wall ofthe enclosure, and d) a spray gun and air hose connected to the threadedend of the pipe to provide atomization air from the turbine to the gunfor paint spraying.
 12. The assembly of claim 11 further comprising adecorative ring threadably received on the threaded end of the exhaustpipe exterior of the enclosure to secure the pipe to the wall of theenclosure.
 13. The assembly of claim 10 wherein the exhaust tube of theturbine is formed of plastic.
 14. The assembly of claim 10 wherein theexhaust tube of the turbine is formed of aluminum.
 15. The assembly ofclaim 10 further comprising an O-ring located between the annularreducer and the exhaust tube of the turbine.